Author | Elizabeth Kolbert |
---|---|
Language | English |
Subject | |
Genre | Nonfiction popular science |
Published | 2014 (Henry Holt and Company) |
Publication place |
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Media type | |
Pages | 319 |
ISBN | 978-0-8050-9299-8 |
576.8/4 | |
LC Class | QE721.2.E97 K65 2014 |
The Sixth Extinction: An Unnatural History is a 2014 nonfiction book written by Elizabeth Kolbert and published by Henry Holt and Company. The book argues that the Earth is in the midst of a modern, man-made, sixth extinction. In the book, Kolbert chronicles previous mass extinction events, and compares them to the accelerated, widespread extinctions during our present time. She also describes specific species extinguished by humans, as well as the ecologies surrounding prehistoric and near-present extinction events. The author received the Pulitzer Prize for General Nonfiction for the book in 2015. [1]
The target audience is the general reader, and scientific descriptions are rendered in understandable prose. The writing blends explanations of her treks to remote areas with interviews of scientists, researchers, and guides, without advocating a position, in pursuit of objectivity. Hence, the sixth mass extinction theme is applied to flora and fauna existing in diverse habitats, such as the Panamanian rainforest, the Great Barrier Reef, the Andes, Bikini Atoll, city zoos, and the author's own backyard. The book also applies this theme to a number of other habitats and organisms throughout the world. After researching the current mainstream view of the relevant peer-reviewed science, Kolbert estimates flora and fauna loss by the end of the 21st century to be between 20 and 50 percent "of all living species on earth". [2] [3] [4] [5] [6] [7]
Kolbert equates current, general unawareness of this issue to previous widespread disbelief of it during the centuries preceding the late 1700s; at that time, it was believed that prehistoric mass extinctions had never occurred. It was also believed that there were no natural forces—including biological ones—powerful enough to extinguish species en masse . Likewise, in our own time, the possible finality presented by this issue results in denialism. However, scientific studies have shown that human behavior disrupts Earth's balanced and interconnected systems, "putting our own survival in danger." Consequently, the Earth's systems currently affected are the global atmosphere, the water cycle, the ocean's heat absorption, ocean acidity (and its effect on coral reefs), soil moisture and drought conditions, plant destruction by pests/non-indigenous fauna or heat stress, heat regulation by the Earth's ice, and so on.
The human species contributes to this disruption—even without intending to—because of our innate capabilities to alter the planet at this stage of our cultural evolution; for instance, we now can harness energy from beneath the Earth's surface. Homo sapiens also can adapt relatively quickly to almost any environment on this planet's surface. Other species, however, have a hard time relocating to new, suitable habitats. They are unable to migrate ahead of current rapid ecological changes or are hampered by artificial barriers such as roadways, cityscapes, and suburban sprawl, which increase discontinuity between viable habitats throughout the world. [2] [3] [4] [5] [6]
Elizabeth Kolbert is a science writer for The New Yorker magazine. She is the author of Field Notes from a Catastrophe , as well as several other books. Her writing focuses on the effects of humans and civilization on our planet's ecosystem. Much of her writing involves her experiences of various locations, as noted above. Previously, she was a reporter for The New York Times . [2] [4] Kolbert resides in Williamstown, Massachusetts, with her husband and children, and she writes in her home office across from Mount Greylock in Massachusetts. [8] Kolbert has been interviewed by national news and media organizations. [9] [10] [11] [12] [13]
Kolbert's decision to write this book was influenced by a 2008 Proceedings of the National Academy of Sciences paper, titled, "Are we in the midst of the sixth mass extinction? A view from the world of amphibians". Subsequently, Kolbert wrote an article for The New Yorker, titled (similarly to her eventual book), "The Sixth Extinction?" [14] Researching this article involved amphibian hunting in Panama. She then realized, "I hadn't scratched the surface, that there was a book there." [7] [15]
The ancestors of frogs crawled out of water around 400 million years ago. 250 million years ago, frogs were the earliest representation of what would become the modern amphibian orders. Amphibians have been on Earth for longer than mammals or birds; they were even here before dinosaurs. Recently, it has been reported that the extinction rate of frogs is increasing. Based on observed extinction rates far beyond expected background extinction rates, we can predict that an event of a catastrophic nature is headed our way. [16] A decade ago, Panamanian golden frogs were plentiful in numbers and easy to find around Panama. However, within the past couple of years, the frogs started to disappear. Kolbert states that studies by the National Zoological Park in Washington, DC, and a mycologist at the University of Maine, have identified the reason for the increased mortality of Panamanian frogs as a type of Chytrid fungus. [17] However, Chytrid fungi are not naturally found in Panama. This left a puzzling question: how did the fungus get to Panama? Evidence indicates that humans were instrumental in how the fungus traveled. Kolbert uses the frog-fungus relationship as a symbol of how humans are introducing invasive species to various environments, where native species would normally have the proper distribution of alleles for their environment.
Kolbert explains how fossils of the American mastodon (Mammut americanum) shaped Georges Cuvier's views on catastrophism. According to Cuvier, there was no reason the mastodon should have died out. The mastodon was large enough to avoid predation, had large enough teeth to consume an abrasive diet, and had other phenotypes that should have increased its chances of survival. Cuvier concluded there must have been sudden and violent catastrophes that caused mass extinctions of viable species. [18] Kolbert uses the mastodon as a symbol for the idea that catastrophe is an important mechanism of extinction.
The great auk was a large flightless bird that lived in the Northern Hemisphere. It had a large, intricately grooved beak. When the first settlers arrived in Iceland, the auk population was probably in the millions. However, the settlers found the auks to be “very good and nourishing meat.” They also used their oily bodies for fuel and fish bait, and their feathers for stuffing mattresses. [19] Despite attempts at protecting the species, by 1844, the last auks were killed. Kolbert uses the great auk as a symbol of how human overexploitation of resources is another important mechanism of extinction.
Kolbert explains that the main cause of the Cretaceous–Paleogene extinction event was not the impact of the asteroid itself. It was the dust created by the impact. The debris from the impact incinerated anything in its path. [20] She states that it is impossible to estimate the full extent of the various species that died out due to this catastrophe. However, one class of animals we know did die out because of the effects of the asteroid's impact, are the ammonites. Kolbert explains that, even though ammonites were 'fit' for their current environment, a single moment can completely change which traits are advantageous and which are lethal. [21]
Kolbert uses the extinction of graptolites and other clades to explain glaciation as a mechanism for extinction. She then explains how, when carbon dioxide levels in the air are high, there typically is an accompanying increase in temperatures and sea level. Right around the time graptolites became extinct, carbon dioxide levels dropped. Temperatures fell and sea levels plummeted. This caused a change in the chemistry of the ocean, which had a devastating impact on life forms. [22] Kolbert states that human activity has transformed between a third and a half of the land surface on the planet. We have dammed most of the major rivers of the world, increased levels of nitrogen higher than can be fixed naturally by terrestrial ecosystems, used more than half of the world's readily accessible freshwater run-off, removed more than one-third of the primary producers of the oceans' coastal waters and changed the composition of the atmosphere by deforestation and fossil fuel combustion. [23]
Since the beginning of the Industrial Revolution, we have seen increasing levels of carbon dioxide in the atmosphere at an alarming rate. Studies show we have added approximately 365 billion tons of it by burning fossil fuels, and an additional 180 billion tons as a result of deforestation. We add another 9 billion tons or so a year, an amount that has been increasing by 6 percent annually. Essentially, we have increased the concentration of carbon dioxide in the air to higher than it has been in the last several million years. [24] Some of this carbon dioxide is being absorbed by our oceans to create carbonic acid. This lowers the pH of our ocean and kills much of our marine life. Kolbert uses the drastic decline in life forms around the Castello Aragonese as a warning sign of what is to come if we continue to increase carbon dioxide levels in the atmosphere. [25]
Coral reefs support thousands of species by providing food and protection. Subsequently, many species have co-evolved with corals. Due to ocean acidification, corals may become extinct by the end of the century. Before the Industrial Revolution, underwater reefs had an aragonite saturation state between 4 and 5. However, if current emission intensities remain as they are today, by 2060, there will no longer be a region above 3.5. This will lead to an increase in the energy needed for calcification. [26] This extra energy that will eventually be expended on calcification is currently vital to corals, as they use it to recover from being eaten away by marine species and battered by waves. Thus, ocean acidification is a mechanism of extinction.
Global warming is most commonly seen as a threat to cold-loving species. As temperatures rise, the ice at the North Pole and South Pole will melt. Any living thing that depends on the ice will be faced with extreme challenges that could ultimately drive them to extinction. [27] Kolbert points out that the poles are not the only places affected by global warming, and that other areas have much higher latitudinal diversity gradients. She discusses the work of scientists who have used measures of species-area relationships to model the possible effects of global warming. The extent to which species are mobile and can relocate to new areas, in response to shifting climate conditions, is predicted to be a significant factor in possible species extinction. This has particular importance for trees and other plant species. Even more difficult to estimate is the extent to which ecological communities of species will be able to tolerate disruptive changes. [28]
Kolbert points out how everything in life is interconnected, and discusses the importance of patch dynamics. Over time, the fragmentation of environmental areas leads to a decrease in the number of species in an area. This occurs, in part, because the size of such "islands" is too small to support a stable number of species members. Also, smaller populations are more vulnerable to these changing events. In addition, the disconnection of islands makes it more difficult for species to reach and recolonize them. One researcher describes this as "an obstacle course for the dispersal of biodiversity." [29] : 189 Kolbert also notes that the habits of many species can be highly specialized to their environment. She explains that one minor change can cause a domino effect in various ecological systems. [30] [31] [32]
Kolbert points out that there is an evolutionary arms race, in which each species must be equipped to defend against their potential predators and need to be more fit than their competition. A species has no defense if it encounters a new fungus, virus, or bacterium. This can be extremely deadly, as it was in the case of the American bats killed by the psychrophilic fungus Geomyces destructans . [33] Another example of this occurred in the 1800s. The American chestnut was the dominant deciduous tree in eastern American forests. Then, a fungus ( Cryphonectria parasitica ) started to cause chestnut blight. It was nearly 100 percent lethal. This fungus was unintentionally imported to the US by humans. [34] Kolbert then explains that global trade and travel are creating a virtual "Pangaea", in which species of all kinds are being redistributed beyond historical geographic barriers. This furthers the first chapter's idea that invasive species are a mechanism of extinction.
The Sumatran Rhino was once so abundant in numbers it was considered an agricultural pest. However, as Southeast Asia's forests were cut down, the rhino's habitat became fragmented. In the 1900s, the rhino population had shrunk to just a few hundred. A captive breeding program was widely regarded as a failure and resulted in the deaths of several rhinos, and it was decades before a single baby was born. Today, there are only one hundred living Sumatran rhinos. [35] Kolbert uses this rhino species to illustrate habitat fragmentation as another mechanism of extinction.
Europe was home to the Neanderthals for at least 100,000 years. Then, about 30,000 years ago, the Neanderthals vanished. Fossil records show that modern humans arrived in Europe 40,000 years ago. Within 10,000 years, Neanderthals were bred out. [36] Through molecular sequencing, scientists have found that there is one to four percent Neanderthal DNA in all non-African humans. This indicates that humans and Neanderthals interbred, and the resulting hybrids reproduced. The pattern continued until Neanderthals were literally bred out. [37] Kolbert states there is every reason to believe that Neanderthals would still exist if it weren't for Homo sapiens.
Kolbert concludes with hope in humanity, pointing to various efforts to conserve or preserve species. Whether meaning to or not, we are deciding which evolutionary pathways will be shut off forever, and which can be left open to flourish.
Some sources for the book include The Song of the Dodo by David Quammen, The Ghost With Trembling Wings by Scott Weidensaul, and reports from Edward O. Wilson, a biologist. The pioneering studies of naturalist Georges Cuvier and geologist Charles Lyell are also referenced. The book's title is similar to a 1995 book title, The Sixth Extinction by Richard Leakey and Roger Lewin. Also included are excerpts from interviews with a forest ecologist, atmospheric scientist Ken Caldeira, wildlife and conservation experts, a modern-day geologist, and fungus researchers in New England and New York State. [4] [6]
On Book Marks, the book received, based mostly on American publications, "rave" reviews with fifteen critic reviews and twelve being "rave" and three being "positive". [38] On The Omnivore, based on British press reviews, the book received an "omniscore" of 4.5 out of 5. [39] On Bookmarks May/June 2014 issue, a magazine that aggregates critic reviews of books, the book received a (4.0 out of 5) based on critic reviews with a critical summary saying, "By mixing reporting trips around the world with interviews with scientists, Kolbert offers a compelling take on how we've altered our environment--from hunting to extinction large mammals to introducing invasive species into delicate ecosystems, damming major rivers, and more". [40]
Bill Gates named the book to his 2014 Summer Reading List. [45]
The great auk, also known as the penguin or garefowl, is a species of flightless alcid that became extinct in the mid-19th century. It was the only modern species in the genus Pinguinus. It is unrelated to the penguins of the Southern Hemisphere, which were named for their resemblance to this species.
The Holocene extinction, or Anthropocene extinction, is the ongoing extinction event caused by humans during the Holocene epoch. These extinctions span numerous families of plants and animals, including mammals, birds, reptiles, amphibians, fish, and invertebrates, and affecting not just terrestrial species but also large sectors of marine life. With widespread degradation of biodiversity hotspots, such as coral reefs and rainforests, as well as other areas, the vast majority of these extinctions are thought to be undocumented, as the species are undiscovered at the time of their extinction, which goes unrecorded. The current rate of extinction of species is estimated at 100 to 1,000 times higher than natural background extinction rates and is increasing. During the past 100–200 years, biodiversity loss and species extinction have accelerated, to the point that most conservation biologists now believe that human activity has either produced a period of mass extinction, or is on the cusp of doing so. As such, after the "Big Five" mass extinctions, the Holocene extinction event has also been referred to as the sixth mass extinction or sixth extinction; given the recent recognition of the Capitanian mass extinction, the term seventh mass extinction has also been proposed for the Holocene extinction event.
Nature is an inherent character or constitution, particularly of the ecosphere or the universe as a whole. In this general sense nature refers to the laws, elements and phenomena of the physical world, including life. Although humans are part of nature, human activity or humans as a whole are often described as at times at odds, or outright separate and even superior to nature.
Extinction is the termination of a taxon by the death of its last member. A taxon may become functionally extinct before the death of its last member if it loses the capacity to reproduce and recover. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" after a period of apparent absence.
Jean Léopold Nicolas Frédéric, baron Cuvier, known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in natural sciences research in the early 19th century and was instrumental in establishing the fields of comparative anatomy and paleontology through his work in comparing living animals with fossils.
The Anthropocene is a rejected proposal for a geological epoch following the Holocene, dating from the commencement of significant human impact on Earth up to the present day. This impact affects Earth's oceans, geology, geomorphology, landscape, limnology, hydrology, ecosystems and climate. The effects of human activities on Earth can be seen for example in biodiversity loss and climate change. Various start dates for the Anthropocene have been proposed, ranging from the beginning of the Neolithic Revolution, to as recently as the 1960s. The biologist Eugene F. Stoermer is credited with first coining and using the term anthropocene informally in the 1980s; Paul J. Crutzen re-invented and popularized the term. However, in 2024 the International Commission on Stratigraphy (ICS) and the International Union of Geological Sciences (IUGS) rejected the Anthropocene Epoch proposal for inclusion in the Geologic Time Scale.
Environmental degradation is the deterioration of the environment through depletion of resources such as quality of air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable. The environmental degradation process amplifies the impact of environmental issues which leave lasting impacts on the environment.
Eldey is a small, uninhabited island about 13 kilometres off the coast of the Reykjanes Peninsula in southwest Iceland. Located west-southwest of Reykjavík, the island of Eldey covers an area of about 3 hectares, and rises to a height of 77 metres (253 ft). Its sheer cliffs are home to large numbers of birds, including one of the largest northern gannet colonies in the world, with around 16,000 pairs. This colony can now be watched live via two webcams that are located on top of the island.
Human impact on the environment refers to changes to biophysical environments and to ecosystems, biodiversity, and natural resources caused directly or indirectly by humans. Modifying the environment to fit the needs of society is causing severe effects including global warming, environmental degradation, mass extinction and biodiversity loss, ecological crisis, and ecological collapse. Some human activities that cause damage to the environment on a global scale include population growth, neoliberal economic policies and rapid economic growth, overconsumption, overexploitation, pollution, and deforestation. Some of the problems, including global warming and biodiversity loss, have been proposed as representing catastrophic risks to the survival of the human species.
Ocean acidification is the ongoing decrease in the pH of the Earth's ocean. Between 1950 and 2020, the average pH of the ocean surface fell from approximately 8.15 to 8.05. Carbon dioxide emissions from human activities are the primary cause of ocean acidification, with atmospheric carbon dioxide levels exceeding 422 ppm. CO2 from the atmosphere is absorbed by the oceans. This chemical reaction produces carbonic acid which dissociates into a bicarbonate ion and a hydrogen ion. The presence of free hydrogen ions lowers the pH of the ocean, increasing acidity. Marine calcifying organisms, such as mollusks and corals, are especially vulnerable because they rely on calcium carbonate to build shells and skeletons.
Future Evolution is a book written by paleontologist Peter Ward and illustrated by Alexis Rockman. He addresses his own opinion of future evolution and compares it with Dougal Dixon's After Man: A Zoology of the Future and H. G. Wells's The Time Machine.
Elizabeth Kolbert is an American journalist, author, and visiting fellow at Williams College.
References to climate change in popular culture have existed since the late 20th century and increased in the 21st century. Climate change, its impacts, and related human-environment interactions have been featured in nonfiction books and documentaries, but also literature, film, music, television shows and video games.
The Panamanian golden frog, also known as Cerro Campana stubfoot toad and other names, is a species of toad endemic to Panama. Panamanian golden frogs inhabit the streams along the mountainous slopes of the Cordilleran cloud forests of west-central Panama. While the IUCN lists it as Critically Endangered, it may in fact have been extinct in the wild since 2007. Individuals have been collected for breeding in captivity in a bid to preserve the species. The alternative common name, Zetek's golden frog, and the epithet zeteki both commemorate the entomologist James Zetek.
Background extinction rate, also known as the normal extinction rate, refers to the standard rate of extinction in Earth's geological and biological history, excluding major extinction events, including the current human-induced Holocene extinction. There have been five mass extinction events throughout Earth's history.
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, invasive species, and climate change. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration.
Field Notes from a Catastrophe: Man, Nature, and Climate Change is a non-fiction environmental science book by Elizabeth Kolbert that was published by Bloomsbury Publishing in 2006. The book documents a series of scientific observations and political processes, bringing attention to the causes and effects of global climate change. In this book, Kolbert is able to make scientific developments accessible to a very wide audience.
The biological and geological future of Earth can be extrapolated based on the estimated effects of several long-term influences. These include the chemistry at Earth's surface, the cooling rate of the planet's interior, the gravitational interactions with other objects in the Solar System, and a steady increase in the Sun's luminosity. An uncertain factor is the pervasive influence of technology introduced by humans, such as climate engineering, which could cause significant changes to the planet. For example, the current Holocene extinction is being caused by technology, and the effects may last for up to five million years. In turn, technology may result in the extinction of humanity, leaving the planet to gradually return to a slower evolutionary pace resulting solely from long-term natural processes.
The Sixth Extinction or Holocene extinction is the ongoing extinction event of species during the present Holocene epoch.
Under a White Sky: The Nature of the Future is a 2021 environmental book by Elizabeth Kolbert. The book follows many of the themes she explored in The Sixth Extinction.
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: CS1 maint: numeric names: authors list (link)For a distinguished and appropriately documented book of nonfiction by an American author that is not eligible for consideration in any other category, Ten thousand dollars ($10,000). Awarded to "The Sixth Extinction: An Unnatural History," by Elizabeth Kolbert (Henry Holt), an exploration of nature that forces readers to consider the threat posed by human behavior to a world of astonishing diversity.
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